The present invention relates to an aerosol producing substrate material for use with a smoking article and in particular to a porous carrier material having substantially absorbed within its pores a tobacco flavor material and a non-aqueous, non-tobacco aerosol forming material. The present invention also relates to methods of preparing the aerosol producing substrate and, in particular, to a one-step and two-step approach. Such substrate materials are especially useful in making smoking articles that produce an aerosol resembling tobacco smoke, but which contain no more than a minimal amount of incomplete combustion or pyrolysis products.
Cigarette-like smoking articles have been proposed for many years, especially during the last 20 to 30 years. See for example, U.S. Pat. Nos, 4,079,742 to Rainer et al; 4,284,089 to Ray; 2,907,686 to Siegel; 3,258,015 and 3,356,094 to Ellis et al.; 3,516,417 to Moses; 3,943,941 and 4,044,777 to Boyd et al.; 4,286,604 to Ehretsmann et al.; 4,326,544 to Hardwick et al.; 4,340,072 to Bolt et al.; 4,391,285 to Burnett; 4,474, 191 to Steiner; and European Patent Application No. 117,355 (Hearn).
As far as the present inventors are aware, none of the foregoing smoking articles or tobacco substitutes have ever realized any commercial success and none have ever been widely marketed. The absence of such smoking articles from the marketplace is believed to be due to a variety of reasons, including insufficient aerosol generation, both initially and over the life of the product, poor taste, off-taste due to thermal degradation of the smoke former and/or flavor agents, the presence of substantial pyrolysis products and sidestream smoke, and unsightly appearance.
Thus, despite decades of interest and effort, there is still no smoking article on the market which provides the benefits and advantages associated with conventional cigarette smoking, without delivering considerable quantities of incomplete combustion and pyrolysis products
In late 1985, a series of foreign patents were granted or registered disclosing novel smoking articles capable of providing the benefits and advantages associated with conventional cigarette smoking, without delivering appreciable quantities of incomplete combustion or pyrolysis products. The earliest of these patents was Liberian Patent No. 13985/3890, issued Sept. 13, 1985. This patent corresponds to a later published European Patent Application, Publication No. 174,645, published Mar. 19, 1986.